Many types of medical equipment employ a diagnostic device, such as an ultrasound scanning head, which needs to be freely movable in all directions within a given space in order to apply it to select portions of a reclining or otherwise stationary patient. A preferred approach is to utilize a segmented arm assembly, depending outwardly from a fixed, vertically adjustable standard. Typically, the arm assembly is above the patient, and includes three or so arm segments separated by horizontal pivot joints, with each segment being rotatable in the horizontal plane.
Such systems obviously afford great flexibility to the operator, in terms of positioning the diagnostic head in contact with the patient, and for the most part they allow the operator a rather complete and precise control. There exists a problem, however, in such segmented assemblies when the respective segments are in alignment or approximately in alignment. During such times, the operator often has difficulty, when manipulating the arrangement from the outside perimeter of the assembly, in insuring that the several joints fold or rotate in the right sequence, and in the right direction. Chiefly, this is because the operator lacks a point of leverage with respect to the respective segments.
It is a principal object of the present invention to provide automatic sequencing controls whereby the operator who utilizes a multiple segment overhead arm assembly has requisite control over each individual segment, in terms of both direction and extent of rotation, whereby a diagnostic head may be properly and controllably applied to the patient.